Your search resulted in 411 documents. Displaying 25 entries per page.
Photo-discoloration and Degradation of Wood and its Stabilisation by Modification with Benzoyl Chloride
2004 - IRG/WP 04-40274
Photo degradation of Pinus roxburghii (chir pine) and Hevea brasiliensis (rubber wood) was studied under artificial accelerated weathering conditions in a Xenon test chamber. The irradiated samples were analyzed for color changes and chemical changes. Analysis of colour changes in wood surfaces by UV-Vis. irradiation was carried out using a colour measuring (CIELAB) system and chemical changes ...
K K Pandey
A comparative study of CCA type C and B treated poles in service
1993 - IRG/WP 93-50001-05
CCA K33 type B and C treated utility poles, 9 pieces of each treatment type, were analyzed for preservative retention after 11 years in use. Borings were taking 1 m above and 0.3 m below the ground line. Also total amount of copper, chromium and arsenic was determined in soil surrounding the poles. The solubility of these active components in soil was monitored by using different leaching procedur...
A J Nurmi
Effect of vegetable compost on leaching of CCA components from treated wood - An Update
1995 - IRG/WP 95-50048
In an earlier study, the effect of compost on CCA-C leaching was compared with leaching losses under different exposure conditions. Small treated cubes (25 mm³) were destructively sampled over a 12 month period and the residual CCA determined for exposure to compost in a compost bin, exposed to natural rain and buried in soil. This study provides a comparison after 3 years of samples exposed to c...
P A Cooper, Y T Ung
Xenon simulation of natural weathering of external joinery preserving - Finishing systems
1992 - IRG/WP 92-2412
Semitransparent wood stains ('lazures') for external joinery have developed by means of product combination towards complete wood finishing systems that are easy to applicate, have a good weathering resistance and low maintenance cost. The search for enhanced formulations and the possibilities to standardize these products or treatment systems are always facing long periods of we...
J Van Acker, M Stevens, M Nys
Corrosion of zinc-coated nails used with preservative-treated western red cedar shakes in service
1982 - IRG/WP 3197
The corrosion of metal fasteners used with certain wood species and with preservative-treated woods can be a serious problem. The chemical reactivity of western red cedar (Thuja plicata Donn) extractives to iron and copper is well documented and wood preservative treatments containing copper, chromium, and/or ammonium hydroxide can be expected to similarly attack some metals. This problem is compo...
R S Smith, E L Johnson, A J Cserjesi
Natural weathering of wood in a sunny climate effects on surface chemistry and paint adhesion
1997 - IRG/WP 97-20109
Radiata pine veneers and blocks were exposed to natural weathering under Australian summer conditions over a period of 30 days. Infrared spectroscopy revealed that there was perceptible surface delignification after 4 hours exposure, substantial surface delignification after 3 days exposure and almost complete surface delignification after 6 days. Viscometry determinations on holocellulose samples...
P D Evans, P D Thay, K J Schmalzl
Life-cycle assessement of treated wood: A view from the roa
1996 - IRG/WP 96-50078
Life Cycle Assessement (LCA) is being used increasingly as a tool to structure information on the environmental characteristics of material and processes. This paper is based on the experience gained from our LCA studies on treated wood products over the last 4 years. The comprehensive and logical examination af the information available on treated timber provided by LCA has allowed identification...
W Hillier, R J Murphy, D J Dickinson, J N B Bell
Environmental risk assessment of treated timber in service: The Environment Focus Group approach
2000 - IRG/WP 00-50162
In the context of the Biocidal Products Directive (98/8/EC), and of the OECD work on wood preservatives, the Environment Focus Group (EFG), comprising 8 institutes and the European Wood Preservative Manufacturers Group, has been working on the environmental risk assessment of treated timber in service. A literature review of emissions from treated timber has revealed that very little existing data...
G Deroubaix, G Labat, I Le Bayon, S Legay, P Marchal, C Yrieix, E Melcher, R-D Peek, S De Geyter, J Van Acker, W J Homan, D J Dickinson, R J Murphy, E D Suttie, A J Nurmi, A-C Ritschkoff, D Rudolph, I Stephan, D Aston, E F Baines, J B Simonin
Comparative life cycle assessment of Swiss railroad sleepers
1998 - IRG/WP 98-50117
The results of an environmental LCA carried out on railway sleepers made of prestressed concrete, sectional steel and creosote impregnated beech as used on main lines of Switzerland's railways are presented. All extractions from and insertions into the environment which were connected with the manufacture, use and disposal of the different types of sleeper were inventoried and assessed, i...
T Künniger, K Richter
Improving the weather resistance of glue-laminated jarrah and karri
1994 - IRG/WP 94-40017
Surface modification and dimensional stabilisation significantly increased the dry and wet shear strength of karri and jarrah lap-shear specimens (laminates) bonded with resorcinol formaldehyde. The combination of surface modification (sanding/sodium hydroxide treatment), and furfurylation produced the highest dry and wet shear strengths. Acetylated laminates had the lowest dry bond strength, but ...
J Balfas, P D Evans
Laboratory tests on light organic solvent preservatives for use in Australia. - Part 6: Soft rot resistance of three fully formulated preservatives on different timber substrates
2000 - IRG/WP 00-30245
The above-ground soft rot resistance of substrates treated with three fully formulated light organic solvent preservatives (Cuprivac Green WR, Impresol WR 205 and Vacsol) was studied using a modified vermiculite burial method. The substrates were sapwood of Pinus elliottii and P. radiata and heartwood of Eucalyptus regnans, Pseudotsuga menziesii, Shorea sp. (a lower and a higher density source) an...
G C Johnson, M A Tighe, J D Thornton
Natural exposure weathering tests: Their role in the assessment of wood preservative efficacy
1993 - IRG/WP 93-20006
Previous work has demonstrated the potential and usefulness of natural ageing procedures in e evaluation of wood preservative efficacy. This results from the combination of physico-chemical influences and microbiological interactions with both substrate and wood preservative. In this paper, results are presented for a range of biocide types. Discussions are centred on the value of natural exposure...
G R Williams, J Brown
Durability of Wood Plastic Composites Relative to Natural Weathering and Preservative Treatment With Zinc Borate
2005 - IRG/WP 05-40316
Wood-Plastic Composites (WPCs) used for decking have experienced dramatic increases in North America, averaging 25% growth per annum since 1998. A key factor contributing to this growth has been the successfully communicated message that they are "virtually maintenance free". The common perception being that the wood fiber is completely encapsulated by the thermoplastic resin, minimizing the pot...
M E Mankowski, F M Ascherl, M J Manning
Correlation between changes in colour and chemical composition during photo-degradation of wood surfaces
2005 - IRG/WP 05-40301
Changes in colour of wood (yellowing) during photo degradation or weathering reflect chemical changes in wood. Therefore, the relationship between changes in chemical composition and CIELAB colour parameters is very important to characterize photodegradation of lignocellulosic surfaces. In this study, the changes in chemical composition and yellowing due to photo-degradation was studied by expos...
K K Pandey
Properties of hot oil treated wood and the possible chemical reactions between wood and soybean oil during heat treatment
2005 - IRG/WP 05-40304
Thermal treatment with hot oil as the heating media based on the original idea from oil-heat treatment in Germany was investigated. The treatment was mainly carried out at 200ºC and 220ºC for 2 hours and 4 hours, and the wood species were mainly spruce and fir. This paper focuses on the difference between soybean oil and palm oil and the possible chemical reactions between wood and soybean oil. ...
Jieying Wang, P A Cooper
Effect of angle of exposure on degradation of radiata pine during weathering trials
1988 - IRG/WP 2301
The importance of angle of exposure on the degree of weathering of materials has not been adequately resolved. In conventional tests, specimens are exposed at an angle of 45° facing the equator, but more recently experiments on polymeric materials have suggested that an angle of 0° may be preferable since this angle maximises levels of received ultra-violet radiation. In this paper the degradati...
P D Evans
The influence of copper (II) chemicals on the weathering of treated wood. Part 1: ACQ treatment of wood on its weathering
1994 - IRG/WP 94-30040
Wood weathering can be accelerated by alkylammonium compound (AAC) treatment, and slowed by ammoniacal copper quat (ACQ) treatment. This study aims at investigating the influence of ACQ treatment of wood, especially the present of copper (II), on its weathering. ACQ, CCA and DDAC treated microtomed sections of southern yellow pine earlywood were prepared and naturally weathered for five periods, t...
Ruiying Liu, J N R Ruddick, L Jin
Laboratory tests on artificial weathering of Quercus rubra crossties
1986 - IRG/WP 2252
Clear red oak (Quercus rubra) blocks were used to evaluate various types of accelerated aging tests including boil, steaming, and cyclic weathering. It was found that the repeated vacuum and pressure treatment of wood in water, steaming, oven-dry, and freezing appeared to be most effective in reducing the MOE in compression and hardness modules of wood specimens. Red oak crossties which were press...
P Chow, A J Reinschmidt, E J Barenberg, S L Lewis
Fixation of copper-chrome-arsenic treated timber: A comparison of leaching methodologies
1996 - IRG/WP 96-50075
Five packs of kiln dried radiata pine heartwood were treated with copper-chrome-arsenic preservative treated, utilising a modified Bethell treatment schedule. Two methods of determining the level of preservative fixation were compared. These included the diphenylcarbazide method and simulated rainfall testing. The fixation levels were generally higher for tests involving simulated rain leaching. F...
S Walley, P R S Cobham, P Vinden
Resistance of painted wood to mould fungi. Part 3. The effect of weathering, wood substrate and fungicides on mould growth
1998 - IRG/WP 98-10284
The effect of 6 month outdoor weathering on the resistance of acrylate paint systems on different types of pine and spruce sapwood to mould fungi was studied. Dipping into the preservative prior to painting, a primer with and without a fungicide (propiconazole + IPBC 0.50 + 0.2%) and a topcoat with and without a fungicide (propiconazole + IPBC 0.25 + 0.12%) were combinations of the treatments stud...
H Viitanen, P Ahola
Remedial ground-line treatment of CCA poles in service. Results of chemical and microbiological analyses 6 months after treatment
1986 - IRG/WP 3388
CCA-treated poles in service with incipient internal soft rot were remedially treated by inserting borate rods, brushing with a boron/glycol solution and injecting boric acid paste, copper/creosote paste or a commercial product (DFCK paste). The spread of active chemicals in the treated zone as well as the change in microflora have been studied with time. After six months chemicals had spread to m...
B Henningsson, H Friis-Hansen, A Käärik, M-L Edlund
Quality of timber impregnated with preservatives of class AB
after three years in service
2002 - IRG/WP 02-20241
Quality of impregnated timber is most often expressed by penetration and retention of the preservative used. Relatively less information is available about the performance of the final product, e.g. decks, panels etc. regarding product’s surface checks, deformations and overall appearance. Together with the timber durability, the above mention features are of esthetical importance in the above g...
N Terziev
Solvent extraction of CCA-C from out-of-service wood
1998 - IRG/WP 98-50107
Elimination of CCA from decommissioned wood prior to disposal is a major environmental issue. One approach is to extract CCA from treated wood, then reuse the 'clean' (may contain CCA, but below hazardous level) wood materials for manufacturing wood-based composites. In the present paper, we focus on effective leaching processes, selection of leaching agents and optimum leaching ...
K M F Kazi, P A Cooper
Remedial ground-line treatment of CCA poles in service. A final report after 60 months' testing
1989 - IRG/WP 3534
Remedial treatment of CCA treated utility poles of Pinus sylvestris with incipient decay was carried out in 1983 and the results of chemical and microbiological analyses 6 months after treatment were reported in Document No: IRG/WP/3388 while microbiological studies 12 and 28 months after treatment as well as chemical analyses of poles treated with boron rods or boric acid paste 28 months after tr...
B Henningsson, H Friis-Hansen, A Käärik, M-L Edlund
Economical analysis of the chemicals used on remediation copper, chromium and arsenic from out of service CCA-treated utility poles in Turkey
2004 - IRG/WP 04-50217
There are 20.7 million hectare forested area in Turkey. However, the wood products supplies do not meet demand. One of the wooden products is the utility poles. In Turkey, impregnation of utility poles has been started since 1960's and 5 million utility poles have been used until today since then. Although life time of the utility poles may vary depending on climatic conditions, average s...
E D Gezer, D Toksoy, Ü C Yildiz